When converting a .cbz comic to EPUB Calibre removes the ComicInfo.xml file and just keeps the .jpeg files. ComicInfo.xml contains all the metadata for the comic.

Is there any way to keep this file in the resulting epub file?
Maybe an option could be added to "Convert Book -> Comic Input" for keeping the "ComicInfo.xml" in .cbz files when converting to epub.

If kept this file should probably be added to the manifest in content.opf also.

This way you can have an epub file that is also a cbz file in disguise. It is then easy to open .epub files in .cbz only readers just by changing the .epub filename extension to .cbz and still retain all metadata.